Using boards' heaters ?

[TheSquiffy]

I'm currently making the list of items to buy to build a 6x lanes and I was wondering if active heaters could be added to spool chambers.

EBB36/EBB42 boards have heater connectors, could these be used to warm the filament chamber like the AMS2 Pro?

I.e. on ALI there are flexyble heater pads like item 4001263528634, 100x45 or 110x55 at 24V that could fit:

Also, the wiring hatch should be adapted to include a 2 pin JST:

I'm unsure about the temperature measurement and if klipper modifications are needed to keep these under control (i.e. <65°C) to avoid melting....

[igiannakas]

Yes they electrically could as the hardware to control a heater, fan and a thermistor is there.

Doing so safely and without causing a fire risk is a different story though. Detecting and avoiding runaway scenarios, measuring element temperature, safety cut off, and a fan is imho absolutely necessary.

We’re investigating feasibility of such a mod/change but it has to be safe as a top priority!

[renekar]

The approach of integration a filament drying function is a very interesting one. As I'm actually also preparing for the build, u can consider me as a contributor/ tester.

A thermal fuse might be sufficient to react on runaways.

[TheSquiffy]

It should be possible to fit a 3010 fan / 24V to circulate the air inside the spool box.

The heating pad should have a thermistor and a thermal fuse glued on it with red silicon, like the way we used to attach the fuse to voron beds.
All the signals should be easily routed down to the hatch with some zip ties:

Additional wires would be:

• 2x the heater pad
• 2x for fan
• 2x for the thermistor, like a common NTC

On the EBB boards there should still be a fan and thermistor ports available to handle them.

:-)

[renekar]

Maybe a PTC heater would be a good alternative to the heater pad, as it comes directly with an aluminum housing and could be screwed with ceramic washer as isolator to the wall.

[TheSquiffy]

I think PTC heaters are a bit more space consuming where flexy pads would better fit, but thanks for suggesting :-)

In the meantime, I designed a board to completely replace current complexity of wiring through the EBB boards (I don't really like canbus, sorry!)

It will be using USB instead powered by a Nitehawk Hexa board which should fit my own needs (6x lanes), provinding enough power for the heaters.

Here is a shoot of my WIP (please be kind with me!) :-)

It will be more like a prototype yet, wires would be soldered from the board directly to two molex connectors under the spool-box, still keeping it sealed.

This will be the final wiring, simplified:

The white cross objects are joiners, because I cannot print lane bases with my 250x250 printer, thus I split them.

@renekar : feel free to reach me on voron discord for further discussion, I don't think this issue thread should be polluted with my things any further.

[igiannakas]

Would you mind raising a PR for the split bottom box for a 250 printer under the user mods folder? Your approach is pretty neat! @TheSquiffy

[RavenousXIV]

I personally think the PTC Heater is a neat solution, not sure I'd be comfortable with a heater pad, I've had one runaway. Not fun.

[igiannakas]

We’ve been actively experimenting with ptc heating elements with their corresponding dense fin stacks (24V) driven by the EBBs together with their required safety features (thermistor on the element, thermal fuse). We have a working concept but more work needs to be done. The idea is to fit it where the desiccant pack goes, allowing for a modular solution.

There’s plenty to do - test different heater wattages, fan arrangements and heater temperatures to find the limits of what is safe and effective at drying spools.

[RavenousXIV]

Neat, you guys are doing awesome work, just started to print my first parts 👍🏼

[TheSquiffy]

Hey all

Totally aligned on safety first: thermistor on the element, thermal fuse, sane limits, and proper airflow/fan to avoid runaway scenarios.

In parallel, I’ve been working for the past weeks on a USB-based alternative (I’m personally trying to avoid CANbus / EBB wiring complexity). I received a Nitehawk Hexa as USB/power backbone and I’m prototyping a lane board to simplify wiring and feed up to 6 lanes/heaters (first prototype is going to production soon).

If you’re interested, I’m happy to share CAD/PCB + wiring approach and collaborate via PRs (also: I can open the PR for the 250mm split bottom box you asked about 🙂).

To keep this issue clean, I’m also happy to move the deeper discussion somewhere else (Discord / whatever you prefer) - just tell me where.

[igiannakas]

I’d love to start a PR for the board work if you can and a separate on the 250 bases.

We’re also on both the annex engineering and happy hare discord if you’d like to join the conversation there.